Dataset for Classification of Symmetric Hadamard Matrices of Orders Up to 32

This dataset contains classifications of symmetric Hadamard matrices of orders 2, 4, 8, 12, 16, 20, 24, 28, 32. For each order n, the file n.txt contains one symmetric representative from each equivalence class of Hadamard matrices of order n that contains a symmetric Hadamard matrix. The numbers of such equivalence classes are given below. Order (n) Number of equivalence classes 2 1 4 1 8 1 12 1 16 3 20 3 24 11 28 91 32 3231 In the text files, matrix entries are encoded using + for 1 and - for -1. The order of the automorphism group of each matrix is given immediately below the matrix.